[meta] Use standard JavaScript/EcmaScript features

[tschuster]

The shared adblockplus code contains some amount of SpiderMonkey specific code. We should still allow ES6 code, because we already use a lot of those features. (e.g. let) When other browsers/engines catch up we may be able remove parts of the jshydra JS rewriting code.

• for each #301
• function () expression (function without {})
• defineGetter defineSetter (should use Object.defineProperty)
• Cu.import (in the far future we might be able to use modules)

[philll]

Is the information in this issue complete and are we willing to do the changes? If yes, please set it to "ready". As explained in the meeting today, please also give some testing hints.

[tschuster]

Okays sorry, for context: These are purely internal changes to the code to use different features. There should be no testing required, especially because it's should not be possible from an user/tester point of view to see any UI or behavior change at all. I am also working on this, so I am taking it. I am not sure it's easy to tell when we are done, but right now we still use JavaScript features that aren't standard.

[philll]

You maybe didn't get my point here: Testing is about proving your changes to a) do what they ought to and b) ensure the rest is still working as before. As each and every code change implies a risk of damaging some sort of functionality, you should always provide enough background and/or testing information to lead testers to be able to do the above. If you changes are at a very low level, just go up in the code logic until you can provide funtion-level hints. Please also note that a codereview can never replace testing. The mid-term goal here is to not allow any code change to get released without former testing.

[sebastian]

The last sub-issue has just been fixed. Therefore, closing the meta issue now.